MJO异常对东亚季风涌的作用及其对我国东部延伸期天气影响的研究

This project based on the atmospherical ISO (Intra-Seasonal Oscillation) theories, we will study the influence of MJO (Madden-Julian Oscillation) and East Asian monsoon surge on the Asian Monsoon and the extended weather in Eastern China. Many results indicate that the influence of MJO on the extended weather (such as the persistent precipitation process) in Eastern China by means of affect the northward propagation of the ISO in Asian summer monsoon. The some research found that the Asian monsoon ISO will be affected by MJO anomaly activities and along the three special ways northward propagation, which located in Arabic Sea, the Bay of Bengal, the South China Sea and Equatorial West Pacific. The unusual northward propagation of ISO will cause the anomalous rainfall over the Bay of Bengal, the Southeast Asia and the East Asian area. The activities of tropical MJO should be linked the Asian monsoon, there are some interaction relationships between MJO and summer monsoon surge. These relationships will affect the extremely weather events over the Eastern China. The activity status of atmospherically ISO could be as the very important general circulation signal which should do some researches in-deeply. This research would be very useful for the area extended weather forecast. In order to better understanding and predicting the variation of Asian monsoon, this project will pay more attention for the study in the affect to the propagation of summer monsoon surge by MJO's activities. We will analysis the interacted relationships that between MJO and Asian summer monsoon surge. Using the atmospherically ISO theories, the project will study the physical mechanism and new method of the extended weather forecast in Eastern China. The results of this project will provide dependable principle for improving the capability of meteorological services in Eastern China.

本项目以季节内振荡（ISO）理论为基础，研究MJO（Madden-Julian Oscillation）和夏季风涌对我国东部延伸期天气过程的影响。研究表明MJO通过影响亚洲季风中ISO的向北传播（季风涌）进而对我国东部地区的降水过程产生影响。MJO与亚洲季风间存在密不可分的相互作用，这种作用对极端天气事件的发生具有重要影响。大气ISO活动状况作为东亚地区夏季降水的重要环流背景信号而需要开展深入研究，这对提高延伸期（10-30d）天气预报有重要科学意义。为更好了解和预测亚洲季风的变异，本项目将重点研究MJO的持续异常变化规律及其对亚洲夏季风中季风涌传播的影响；将研究MJO与亚洲季风涌间的相互作用，揭示这种关系对东部地区持续性降水过程的影响；研究我国东部地区延伸期天气过程的物理机理。本项目的研究结果可为提高对我国东部地区的气象服务能力提供可靠的理论依据。

本项目使用了CPC提供的MJO指数资料、澳大利亚气象台提供的RMM指数资料、NECP再分析资料（包括风场、温压场等）、GODAS次表层海温资料、CMAP降水资料、全国776站点降水资料等数据进行分析：定义出描述MJO持续异常特征的IIP指数，分析了MJO持续异常的周期特征和环流特征；在发现MJO持续异常与ENSO极强相关关系的同时，并通过合成分析和个例年举例探讨了MJO持续异常影响太平洋海温异常的内在机制；研究了MJO持续异常对亚洲季风区夏季雨带推进的影响；对MJO持续异常与前期海温之间存在的关系进行了讨论，提出了影响夏季MJO持续异常特征的主要原因。